AVCodecContext Struct Reference

main external API structure. More...

#include <avcodec.h>

Data Fields

const AVClassav_class
 information on struct for av_log More...
 
int log_level_offset
 
enum AVMediaType codec_type
 
const struct AVCodeccodec
 
enum AVCodecID codec_id
 
unsigned int codec_tag
 fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A'). More...
 
void * priv_data
 
struct AVCodecInternal * internal
 Private context used for internal data. More...
 
void * opaque
 Private data of the user, can be used to carry app specific stuff. More...
 
int bit_rate
 the average bitrate More...
 
int bit_rate_tolerance
 number of bits the bitstream is allowed to diverge from the reference. More...
 
int global_quality
 Global quality for codecs which cannot change it per frame. More...
 
int compression_level
 
int flags
 AV_CODEC_FLAG_*. More...
 
int flags2
 AV_CODEC_FLAG2_*. More...
 
uint8_t * extradata
 some codecs need / can use extradata like Huffman tables. More...
 
int extradata_size
 
AVRational time_base
 This is the fundamental unit of time (in seconds) in terms of which frame timestamps are represented. More...
 
int ticks_per_frame
 For some codecs, the time base is closer to the field rate than the frame rate. More...
 
int delay
 Codec delay. More...
 
int width
 picture width / height. More...
 
int height
 
int coded_width
 Bitstream width / height, may be different from width/height e.g. More...
 
int coded_height
 
int gop_size
 the number of pictures in a group of pictures, or 0 for intra_only More...
 
enum AVPixelFormat pix_fmt
 Pixel format, see AV_PIX_FMT_xxx. More...
 
void(* draw_horiz_band )(struct AVCodecContext *s, const AVFrame *src, int offset[AV_NUM_DATA_POINTERS], int y, int type, int height)
 If non NULL, 'draw_horiz_band' is called by the libavcodec decoder to draw a horizontal band. More...
 
enum AVPixelFormat(* get_format )(struct AVCodecContext *s, const enum AVPixelFormat *fmt)
 callback to negotiate the pixelFormat More...
 
int max_b_frames
 maximum number of B-frames between non-B-frames Note: The output will be delayed by max_b_frames+1 relative to the input. More...
 
float b_quant_factor
 qscale factor between IP and B-frames If > 0 then the last P-frame quantizer will be used (q= lastp_q*factor+offset). More...
 
attribute_deprecated int b_frame_strategy
 
float b_quant_offset
 qscale offset between IP and B-frames More...
 
int has_b_frames
 Size of the frame reordering buffer in the decoder. More...
 
attribute_deprecated int mpeg_quant
 
float i_quant_factor
 qscale factor between P- and I-frames If > 0 then the last P-frame quantizer will be used (q = lastp_q * factor + offset). More...
 
float i_quant_offset
 qscale offset between P and I-frames More...
 
float lumi_masking
 luminance masking (0-> disabled) More...
 
float temporal_cplx_masking
 temporary complexity masking (0-> disabled) More...
 
float spatial_cplx_masking
 spatial complexity masking (0-> disabled) More...
 
float p_masking
 p block masking (0-> disabled) More...
 
float dark_masking
 darkness masking (0-> disabled) More...
 
int slice_count
 slice count More...
 
attribute_deprecated int prediction_method
 
int * slice_offset
 slice offsets in the frame in bytes More...
 
AVRational sample_aspect_ratio
 sample aspect ratio (0 if unknown) That is the width of a pixel divided by the height of the pixel. More...
 
int me_cmp
 motion estimation comparison function More...
 
int me_sub_cmp
 subpixel motion estimation comparison function More...
 
int mb_cmp
 macroblock comparison function (not supported yet) More...
 
int ildct_cmp
 interlaced DCT comparison function More...
 
int dia_size
 ME diamond size & shape. More...
 
int last_predictor_count
 amount of previous MV predictors (2a+1 x 2a+1 square) More...
 
attribute_deprecated int pre_me
 
int me_pre_cmp
 motion estimation prepass comparison function More...
 
int pre_dia_size
 ME prepass diamond size & shape. More...
 
int me_subpel_quality
 subpel ME quality More...
 
int me_range
 maximum motion estimation search range in subpel units If 0 then no limit. More...
 
int slice_flags
 slice flags More...
 
int mb_decision
 macroblock decision mode More...
 
uint16_t * intra_matrix
 custom intra quantization matrix More...
 
uint16_t * inter_matrix
 custom inter quantization matrix More...
 
attribute_deprecated int scenechange_threshold
 
attribute_deprecated int noise_reduction
 
int intra_dc_precision
 precision of the intra DC coefficient - 8 More...
 
int skip_top
 Number of macroblock rows at the top which are skipped. More...
 
int skip_bottom
 Number of macroblock rows at the bottom which are skipped. More...
 
int mb_lmin
 minimum MB Lagrange multiplier More...
 
int mb_lmax
 maximum MB Lagrange multiplier More...
 
attribute_deprecated int me_penalty_compensation
 
int bidir_refine
 
attribute_deprecated int brd_scale
 
int keyint_min
 minimum GOP size More...
 
int refs
 number of reference frames More...
 
attribute_deprecated int chromaoffset
 
int mv0_threshold
 Note: Value depends upon the compare function used for fullpel ME. More...
 
attribute_deprecated int b_sensitivity
 
enum AVColorPrimaries color_primaries
 Chromaticity coordinates of the source primaries. More...
 
enum AVColorTransferCharacteristic color_trc
 Color Transfer Characteristic. More...
 
enum AVColorSpace colorspace
 YUV colorspace type. More...
 
enum AVColorRange color_range
 MPEG vs JPEG YUV range. More...
 
enum AVChromaLocation chroma_sample_location
 This defines the location of chroma samples. More...
 
int slices
 Number of slices. More...
 
enum AVFieldOrder field_order
 Field order. More...
 
int sample_rate
 samples per second More...
 
int channels
 number of audio channels More...
 
enum AVSampleFormat sample_fmt
 audio sample format More...
 
int frame_size
 Number of samples per channel in an audio frame. More...
 
int frame_number
 Frame counter, set by libavcodec. More...
 
int block_align
 number of bytes per packet if constant and known or 0 Used by some WAV based audio codecs. More...
 
int cutoff
 Audio cutoff bandwidth (0 means "automatic") More...
 
uint64_t channel_layout
 Audio channel layout. More...
 
uint64_t request_channel_layout
 Request decoder to use this channel layout if it can (0 for default) More...
 
enum AVAudioServiceType audio_service_type
 Type of service that the audio stream conveys. More...
 
enum AVSampleFormat request_sample_fmt
 Used to request a sample format from the decoder. More...
 
int(* get_buffer2 )(struct AVCodecContext *s, AVFrame *frame, int flags)
 This callback is called at the beginning of each frame to get data buffer(s) for it. More...
 
attribute_deprecated int refcounted_frames
 If non-zero, the decoded audio and video frames returned from avcodec_decode_video2() and avcodec_decode_audio4() are reference-counted and are valid indefinitely. More...
 
float qcompress
 amount of qscale change between easy & hard scenes (0.0-1.0) More...
 
float qblur
 amount of qscale smoothing over time (0.0-1.0) More...
 
int qmin
 minimum quantizer More...
 
int qmax
 maximum quantizer More...
 
int max_qdiff
 maximum quantizer difference between frames More...
 
int rc_buffer_size
 decoder bitstream buffer size More...
 
int rc_override_count
 ratecontrol override, see RcOverride More...
 
RcOverriderc_override
 
int rc_max_rate
 maximum bitrate More...
 
int rc_min_rate
 minimum bitrate More...
 
float rc_max_available_vbv_use
 Ratecontrol attempt to use, at maximum, of what can be used without an underflow. More...
 
float rc_min_vbv_overflow_use
 Ratecontrol attempt to use, at least, times the amount needed to prevent a vbv overflow. More...
 
int rc_initial_buffer_occupancy
 Number of bits which should be loaded into the rc buffer before decoding starts. More...
 
attribute_deprecated int coder_type
 
attribute_deprecated int context_model
 
attribute_deprecated int frame_skip_threshold
 
attribute_deprecated int frame_skip_factor
 
attribute_deprecated int frame_skip_exp
 
attribute_deprecated int frame_skip_cmp
 
int trellis
 trellis RD quantization More...
 
attribute_deprecated int min_prediction_order
 
attribute_deprecated int max_prediction_order
 
attribute_deprecated int64_t timecode_frame_start
 
attribute_deprecated void(* rtp_callback )(struct AVCodecContext *avctx, void *data, int size, int mb_nb)
 
attribute_deprecated int rtp_payload_size
 
attribute_deprecated int mv_bits
 
attribute_deprecated int header_bits
 
attribute_deprecated int i_tex_bits
 
attribute_deprecated int p_tex_bits
 
attribute_deprecated int i_count
 
attribute_deprecated int p_count
 
attribute_deprecated int skip_count
 
attribute_deprecated int misc_bits
 
attribute_deprecated int frame_bits
 
char * stats_out
 pass1 encoding statistics output buffer More...
 
char * stats_in
 pass2 encoding statistics input buffer Concatenated stuff from stats_out of pass1 should be placed here. More...
 
int workaround_bugs
 Work around bugs in encoders which sometimes cannot be detected automatically. More...
 
int strict_std_compliance
 strictly follow the standard (MPEG-4, ...). More...
 
int error_concealment
 error concealment flags More...
 
int debug
 debug More...
 
int err_recognition
 Error recognition; may misdetect some more or less valid parts as errors. More...
 
int64_t reordered_opaque
 opaque 64-bit number (generally a PTS) that will be reordered and output in AVFrame.reordered_opaque More...
 
const struct AVHWAccelhwaccel
 Hardware accelerator in use. More...
 
void * hwaccel_context
 Hardware accelerator context. More...
 
uint64_t error [AV_NUM_DATA_POINTERS]
 error More...
 
int dct_algo
 DCT algorithm, see FF_DCT_* below. More...
 
int idct_algo
 IDCT algorithm, see FF_IDCT_* below. More...
 
int bits_per_coded_sample
 bits per sample/pixel from the demuxer (needed for huffyuv). More...
 
int bits_per_raw_sample
 Bits per sample/pixel of internal libavcodec pixel/sample format. More...
 
attribute_deprecated AVFramecoded_frame
 the picture in the bitstream More...
 
int thread_count
 thread count is used to decide how many independent tasks should be passed to execute() More...
 
int thread_type
 Which multithreading methods to use. More...
 
int active_thread_type
 Which multithreading methods are in use by the codec. More...
 
int thread_safe_callbacks
 Set by the client if its custom get_buffer() callback can be called synchronously from another thread, which allows faster multithreaded decoding. More...
 
int(* execute )(struct AVCodecContext *c, int(*func)(struct AVCodecContext *c2, void *arg), void *arg2, int *ret, int count, int size)
 The codec may call this to execute several independent things. More...
 
int(* execute2 )(struct AVCodecContext *c, int(*func)(struct AVCodecContext *c2, void *arg, int jobnr, int threadnr), void *arg2, int *ret, int count)
 The codec may call this to execute several independent things. More...
 
int nsse_weight
 noise vs. More...
 
int profile
 profile More...
 
int level
 level More...
 
enum AVDiscard skip_loop_filter
 
enum AVDiscard skip_idct
 
enum AVDiscard skip_frame
 
uint8_t * subtitle_header
 Header containing style information for text subtitles. More...
 
int subtitle_header_size
 
attribute_deprecated uint64_t vbv_delay
 VBV delay coded in the last frame (in periods of a 27 MHz clock). More...
 
attribute_deprecated int side_data_only_packets
 Encoding only and set by default. More...
 
int initial_padding
 Audio only. More...
 
AVRational framerate
 
enum AVPixelFormat sw_pix_fmt
 Nominal unaccelerated pixel format, see AV_PIX_FMT_xxx. More...
 
AVPacketSideDatacoded_side_data
 Additional data associated with the entire coded stream. More...
 
int nb_coded_side_data
 
AVBufferRefhw_frames_ctx
 A reference to the AVHWFramesContext describing the input (for encoding) or output (decoding) frames. More...
 
int apply_cropping
 Video decoding only. More...
 
AVBufferRefhw_device_ctx
 A reference to the AVHWDeviceContext describing the device which will be used by a hardware encoder/decoder. More...
 
int hwaccel_flags
 Bit set of AV_HWACCEL_FLAG_* flags, which affect hardware accelerated decoding (if active). More...
 
int extra_hw_frames
 Video decoding only. More...
 

Detailed Description

main external API structure.

New fields can be added to the end with minor version bumps. Removal, reordering and changes to existing fields require a major version bump. sizeof(AVCodecContext) must not be used outside libav*.

Examples:
decode_audio.c, decode_video.c, encode_audio.c, encode_video.c, output.c, and transcode_aac.c.

Definition at line 1216 of file avcodec.h.

Field Documentation

◆ av_class

const AVClass* AVCodecContext::av_class

information on struct for av_log

  • set by avcodec_alloc_context3

Definition at line 1221 of file avcodec.h.

◆ log_level_offset

int AVCodecContext::log_level_offset

Definition at line 1222 of file avcodec.h.

◆ codec_type

enum AVMediaType AVCodecContext::codec_type

Definition at line 1224 of file avcodec.h.

◆ codec

const struct AVCodec* AVCodecContext::codec
Examples:
output.c.

Definition at line 1225 of file avcodec.h.

Referenced by open_audio().

◆ codec_id

enum AVCodecID AVCodecContext::codec_id
Examples:
output.c.

Definition at line 1226 of file avcodec.h.

Referenced by add_video_stream().

◆ codec_tag

unsigned int AVCodecContext::codec_tag

fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').

This is used to work around some encoder bugs. A demuxer should set this to what is stored in the field used to identify the codec. If there are multiple such fields in a container then the demuxer should choose the one which maximizes the information about the used codec. If the codec tag field in a container is larger than 32 bits then the demuxer should remap the longer ID to 32 bits with a table or other structure. Alternatively a new extra_codec_tag + size could be added but for this a clear advantage must be demonstrated first.

  • encoding: Set by user, if not then the default based on codec_id will be used.
  • decoding: Set by user, will be converted to uppercase by libavcodec during init.

Definition at line 1241 of file avcodec.h.

◆ priv_data

void* AVCodecContext::priv_data

Definition at line 1243 of file avcodec.h.

◆ internal

struct AVCodecInternal* AVCodecContext::internal

Private context used for internal data.

Unlike priv_data, this is not codec-specific. It is used in general libavcodec functions.

Definition at line 1251 of file avcodec.h.

◆ opaque

void* AVCodecContext::opaque

Private data of the user, can be used to carry app specific stuff.

  • encoding: Set by user.
  • decoding: Set by user.

Definition at line 1258 of file avcodec.h.

◆ bit_rate

int AVCodecContext::bit_rate

the average bitrate

  • encoding: Set by user; unused for constant quantizer encoding.
  • decoding: Set by libavcodec. 0 or some bitrate if this info is available in the stream.
Examples:
encode_audio.c, encode_video.c, output.c, and transcode_aac.c.

Definition at line 1265 of file avcodec.h.

Referenced by add_audio_stream(), add_video_stream(), main(), and open_output_file().

◆ bit_rate_tolerance

int AVCodecContext::bit_rate_tolerance

number of bits the bitstream is allowed to diverge from the reference.

the reference can be CBR (for CBR pass1) or VBR (for pass2)

  • encoding: Set by user; unused for constant quantizer encoding.
  • decoding: unused

Definition at line 1273 of file avcodec.h.

◆ global_quality

int AVCodecContext::global_quality

Global quality for codecs which cannot change it per frame.

This should be proportional to MPEG-1/2/4 qscale.

  • encoding: Set by user.
  • decoding: unused

Definition at line 1281 of file avcodec.h.

◆ compression_level

int AVCodecContext::compression_level
  • encoding: Set by user.
  • decoding: unused

Definition at line 1287 of file avcodec.h.

◆ flags

int AVCodecContext::flags

AV_CODEC_FLAG_*.

  • encoding: Set by user.
  • decoding: Set by user.
Examples:
output.c, and transcode_aac.c.

Definition at line 1295 of file avcodec.h.

Referenced by add_audio_stream(), add_video_stream(), and open_output_file().

◆ flags2

int AVCodecContext::flags2

AV_CODEC_FLAG2_*.

  • encoding: Set by user.
  • decoding: Set by user.

Definition at line 1302 of file avcodec.h.

◆ extradata

uint8_t* AVCodecContext::extradata

some codecs need / can use extradata like Huffman tables.

MJPEG: Huffman tables rv10: additional flags MPEG-4: global headers (they can be in the bitstream or here) The allocated memory should be AV_INPUT_BUFFER_PADDING_SIZE bytes larger than extradata_size to avoid problems if it is read with the bitstream reader. The bytewise contents of extradata must not depend on the architecture or CPU endianness.

  • encoding: Set/allocated/freed by libavcodec.
  • decoding: Set/allocated/freed by user.

Definition at line 1315 of file avcodec.h.

◆ extradata_size

int AVCodecContext::extradata_size

Definition at line 1316 of file avcodec.h.

◆ time_base

AVRational AVCodecContext::time_base

This is the fundamental unit of time (in seconds) in terms of which frame timestamps are represented.

For fixed-fps content, timebase should be 1/framerate and timestamp increments should be identically 1.

  • encoding: MUST be set by user.
  • decoding: the use of this field for decoding is deprecated. Use framerate instead.
Examples:
encode_video.c, and output.c.

Definition at line 1327 of file avcodec.h.

Referenced by add_video_stream(), encode_audio_frame(), get_audio_frame(), get_video_frame(), main(), and write_video_frame().

◆ ticks_per_frame

int AVCodecContext::ticks_per_frame

For some codecs, the time base is closer to the field rate than the frame rate.

Most notably, H.264 and MPEG-2 specify time_base as half of frame duration if no telecine is used ...

Set to time_base ticks per frame. Default 1, e.g., H.264/MPEG-2 set it to 2.

Definition at line 1336 of file avcodec.h.

◆ delay

int AVCodecContext::delay

Codec delay.

Video: Number of frames the decoded output will be delayed relative to the encoded input.

Audio: For encoding, this field is unused (see initial_padding).

For decoding, this is the number of samples the decoder needs to output before the decoder's output is valid. When seeking, you should start decoding this many samples prior to your desired seek point.

  • encoding: Set by libavcodec.
  • decoding: Set by libavcodec.

Definition at line 1355 of file avcodec.h.

◆ width

int AVCodecContext::width

picture width / height.

Note
Those fields may not match the values of the last AVFrame output by avcodec_decode_video2 due frame reordering.
  • encoding: MUST be set by user.
  • decoding: May be set by the user before opening the decoder if known e.g. from the container. Some decoders will require the dimensions to be set by the caller. During decoding, the decoder may overwrite those values as required while parsing the data.
Examples:
encode_video.c, and output.c.

Definition at line 1372 of file avcodec.h.

Referenced by add_video_stream(), get_video_frame(), main(), and open_video().

◆ height

int AVCodecContext::height
Examples:
encode_video.c, and output.c.

Definition at line 1372 of file avcodec.h.

Referenced by add_video_stream(), get_video_frame(), main(), and open_video().

◆ coded_width

int AVCodecContext::coded_width

Bitstream width / height, may be different from width/height e.g.

when the decoded frame is cropped before being output.

Note
Those field may not match the value of the last AVFrame output by avcodec_receive_frame() due frame reordering.
  • encoding: unused
  • decoding: May be set by the user before opening the decoder if known e.g. from the container. During decoding, the decoder may overwrite those values as required while parsing the data.

Definition at line 1387 of file avcodec.h.

◆ coded_height

int AVCodecContext::coded_height

Definition at line 1387 of file avcodec.h.

◆ gop_size

int AVCodecContext::gop_size

the number of pictures in a group of pictures, or 0 for intra_only

  • encoding: Set by user.
  • decoding: unused
Examples:
encode_video.c, and output.c.

Definition at line 1394 of file avcodec.h.

Referenced by add_video_stream(), and main().

◆ pix_fmt

enum AVPixelFormat AVCodecContext::pix_fmt

Pixel format, see AV_PIX_FMT_xxx.

May be set by the demuxer if known from headers. May be overridden by the decoder if it knows better.

Note
This field may not match the value of the last AVFrame output by avcodec_receive_frame() due frame reordering.
  • encoding: Set by user.
  • decoding: Set by user if known, overridden by libavcodec while parsing the data.
Examples:
encode_video.c, and output.c.

Definition at line 1409 of file avcodec.h.

Referenced by add_video_stream(), get_video_frame(), main(), and open_video().

◆ draw_horiz_band

void(* AVCodecContext::draw_horiz_band) (struct AVCodecContext *s, const AVFrame *src, int offset[AV_NUM_DATA_POINTERS], int y, int type, int height)

If non NULL, 'draw_horiz_band' is called by the libavcodec decoder to draw a horizontal band.

It improves cache usage. Not all codecs can do that. You must check the codec capabilities beforehand. When multithreading is used, it may be called from multiple threads at the same time; threads might draw different parts of the same AVFrame, or multiple AVFrames, and there is no guarantee that slices will be drawn in order. The function is also used by hardware acceleration APIs. It is called at least once during frame decoding to pass the data needed for hardware render. In that mode instead of pixel data, AVFrame points to a structure specific to the acceleration API. The application reads the structure and can change some fields to indicate progress or mark state.

  • encoding: unused
  • decoding: Set by user.
    Parameters
    heightthe height of the slice
    ythe y position of the slice
    type1->top field, 2->bottom field, 3->frame
    offsetoffset into the AVFrame.data from which the slice should be read

Definition at line 1434 of file avcodec.h.

◆ get_format

enum AVPixelFormat(* AVCodecContext::get_format) (struct AVCodecContext *s, const enum AVPixelFormat *fmt)

callback to negotiate the pixelFormat

Parameters
fmtis the list of formats which are supported by the codec, it is terminated by -1 as 0 is a valid format, the formats are ordered by quality. The first is always the native one.
Note
The callback may be called again immediately if initialization for the selected (hardware-accelerated) pixel format failed.
Warning
Behavior is undefined if the callback returns a value not in the fmt list of formats.
Returns
the chosen format
  • encoding: unused
  • decoding: Set by user, if not set the native format will be chosen.

Definition at line 1451 of file avcodec.h.

◆ max_b_frames

int AVCodecContext::max_b_frames

maximum number of B-frames between non-B-frames Note: The output will be delayed by max_b_frames+1 relative to the input.

  • encoding: Set by user.
  • decoding: unused
Examples:
encode_video.c, and output.c.

Definition at line 1459 of file avcodec.h.

Referenced by add_video_stream(), and main().

◆ b_quant_factor

float AVCodecContext::b_quant_factor

qscale factor between IP and B-frames If > 0 then the last P-frame quantizer will be used (q= lastp_q*factor+offset).

If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).

  • encoding: Set by user.
  • decoding: unused

Definition at line 1468 of file avcodec.h.

◆ b_frame_strategy

attribute_deprecated int AVCodecContext::b_frame_strategy
Deprecated:
use encoder private options instead

Definition at line 1473 of file avcodec.h.

◆ b_quant_offset

float AVCodecContext::b_quant_offset

qscale offset between IP and B-frames

  • encoding: Set by user.
  • decoding: unused

Definition at line 1481 of file avcodec.h.

◆ has_b_frames

int AVCodecContext::has_b_frames

Size of the frame reordering buffer in the decoder.

For MPEG-2 it is 1 IPB or 0 low delay IP.

  • encoding: Set by libavcodec.
  • decoding: Set by libavcodec.

Definition at line 1489 of file avcodec.h.

◆ mpeg_quant

attribute_deprecated int AVCodecContext::mpeg_quant
Deprecated:
use encoder private options instead

Definition at line 1494 of file avcodec.h.

◆ i_quant_factor

float AVCodecContext::i_quant_factor

qscale factor between P- and I-frames If > 0 then the last P-frame quantizer will be used (q = lastp_q * factor + offset).

If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).

  • encoding: Set by user.
  • decoding: unused

Definition at line 1504 of file avcodec.h.

◆ i_quant_offset

float AVCodecContext::i_quant_offset

qscale offset between P and I-frames

  • encoding: Set by user.
  • decoding: unused

Definition at line 1511 of file avcodec.h.

◆ lumi_masking

float AVCodecContext::lumi_masking

luminance masking (0-> disabled)

  • encoding: Set by user.
  • decoding: unused

Definition at line 1518 of file avcodec.h.

◆ temporal_cplx_masking

float AVCodecContext::temporal_cplx_masking

temporary complexity masking (0-> disabled)

  • encoding: Set by user.
  • decoding: unused

Definition at line 1525 of file avcodec.h.

◆ spatial_cplx_masking

float AVCodecContext::spatial_cplx_masking

spatial complexity masking (0-> disabled)

  • encoding: Set by user.
  • decoding: unused

Definition at line 1532 of file avcodec.h.

◆ p_masking

float AVCodecContext::p_masking

p block masking (0-> disabled)

  • encoding: Set by user.
  • decoding: unused

Definition at line 1539 of file avcodec.h.

◆ dark_masking

float AVCodecContext::dark_masking

darkness masking (0-> disabled)

  • encoding: Set by user.
  • decoding: unused

Definition at line 1546 of file avcodec.h.

◆ slice_count

int AVCodecContext::slice_count

slice count

  • encoding: Set by libavcodec.
  • decoding: Set by user (or 0).

Definition at line 1553 of file avcodec.h.

◆ prediction_method

attribute_deprecated int AVCodecContext::prediction_method
Deprecated:
use encoder private options instead

Definition at line 1558 of file avcodec.h.

◆ slice_offset

int* AVCodecContext::slice_offset

slice offsets in the frame in bytes

  • encoding: Set/allocated by libavcodec.
  • decoding: Set/allocated by user (or NULL).

Definition at line 1569 of file avcodec.h.

◆ sample_aspect_ratio

AVRational AVCodecContext::sample_aspect_ratio

sample aspect ratio (0 if unknown) That is the width of a pixel divided by the height of the pixel.

Numerator and denominator must be relatively prime and smaller than 256 for some video standards.

  • encoding: Set by user.
  • decoding: Set by libavcodec.

Definition at line 1578 of file avcodec.h.

◆ me_cmp

int AVCodecContext::me_cmp

motion estimation comparison function

  • encoding: Set by user.
  • decoding: unused

Definition at line 1585 of file avcodec.h.

◆ me_sub_cmp

int AVCodecContext::me_sub_cmp

subpixel motion estimation comparison function

  • encoding: Set by user.
  • decoding: unused

Definition at line 1591 of file avcodec.h.

◆ mb_cmp

int AVCodecContext::mb_cmp

macroblock comparison function (not supported yet)

  • encoding: Set by user.
  • decoding: unused

Definition at line 1597 of file avcodec.h.

◆ ildct_cmp

int AVCodecContext::ildct_cmp

interlaced DCT comparison function

  • encoding: Set by user.
  • decoding: unused

Definition at line 1603 of file avcodec.h.

◆ dia_size

int AVCodecContext::dia_size

ME diamond size & shape.

  • encoding: Set by user.
  • decoding: unused

Definition at line 1624 of file avcodec.h.

◆ last_predictor_count

int AVCodecContext::last_predictor_count

amount of previous MV predictors (2a+1 x 2a+1 square)

  • encoding: Set by user.
  • decoding: unused

Definition at line 1631 of file avcodec.h.

◆ pre_me

attribute_deprecated int AVCodecContext::pre_me
Deprecated:
use encoder private options instead

Definition at line 1636 of file avcodec.h.

◆ me_pre_cmp

int AVCodecContext::me_pre_cmp

motion estimation prepass comparison function

  • encoding: Set by user.
  • decoding: unused

Definition at line 1644 of file avcodec.h.

◆ pre_dia_size

int AVCodecContext::pre_dia_size

ME prepass diamond size & shape.

  • encoding: Set by user.
  • decoding: unused

Definition at line 1651 of file avcodec.h.

◆ me_subpel_quality

int AVCodecContext::me_subpel_quality

subpel ME quality

  • encoding: Set by user.
  • decoding: unused

Definition at line 1658 of file avcodec.h.

◆ me_range

int AVCodecContext::me_range

maximum motion estimation search range in subpel units If 0 then no limit.

  • encoding: Set by user.
  • decoding: unused

Definition at line 1667 of file avcodec.h.

◆ slice_flags

int AVCodecContext::slice_flags

slice flags

  • encoding: unused
  • decoding: Set by user.

Definition at line 1674 of file avcodec.h.

◆ mb_decision

int AVCodecContext::mb_decision

macroblock decision mode

  • encoding: Set by user.
  • decoding: unused
Examples:
output.c.

Definition at line 1684 of file avcodec.h.

Referenced by add_video_stream().

◆ intra_matrix

uint16_t* AVCodecContext::intra_matrix

custom intra quantization matrix

  • encoding: Set by user, can be NULL.
  • decoding: Set by libavcodec.

Definition at line 1694 of file avcodec.h.

◆ inter_matrix

uint16_t* AVCodecContext::inter_matrix

custom inter quantization matrix

  • encoding: Set by user, can be NULL.
  • decoding: Set by libavcodec.

Definition at line 1701 of file avcodec.h.

◆ scenechange_threshold

attribute_deprecated int AVCodecContext::scenechange_threshold
Deprecated:
use encoder private options instead

Definition at line 1706 of file avcodec.h.

◆ noise_reduction

attribute_deprecated int AVCodecContext::noise_reduction
Deprecated:
use encoder private options instead

Definition at line 1710 of file avcodec.h.

◆ intra_dc_precision

int AVCodecContext::intra_dc_precision

precision of the intra DC coefficient - 8

  • encoding: Set by user.
  • decoding: unused

Definition at line 1718 of file avcodec.h.

◆ skip_top

int AVCodecContext::skip_top

Number of macroblock rows at the top which are skipped.

  • encoding: unused
  • decoding: Set by user.

Definition at line 1725 of file avcodec.h.

◆ skip_bottom

int AVCodecContext::skip_bottom

Number of macroblock rows at the bottom which are skipped.

  • encoding: unused
  • decoding: Set by user.

Definition at line 1732 of file avcodec.h.

◆ mb_lmin

int AVCodecContext::mb_lmin

minimum MB Lagrange multiplier

  • encoding: Set by user.
  • decoding: unused

Definition at line 1739 of file avcodec.h.

◆ mb_lmax

int AVCodecContext::mb_lmax

maximum MB Lagrange multiplier

  • encoding: Set by user.
  • decoding: unused

Definition at line 1746 of file avcodec.h.

◆ me_penalty_compensation

attribute_deprecated int AVCodecContext::me_penalty_compensation
Deprecated:
use encoder private options instead

Definition at line 1753 of file avcodec.h.

◆ bidir_refine

int AVCodecContext::bidir_refine
  • encoding: Set by user.
  • decoding: unused

Definition at line 1760 of file avcodec.h.

◆ brd_scale

attribute_deprecated int AVCodecContext::brd_scale
Deprecated:
use encoder private options instead

Definition at line 1765 of file avcodec.h.

◆ keyint_min

int AVCodecContext::keyint_min

minimum GOP size

  • encoding: Set by user.
  • decoding: unused

Definition at line 1773 of file avcodec.h.

◆ refs

int AVCodecContext::refs

number of reference frames

  • encoding: Set by user.
  • decoding: Set by lavc.

Definition at line 1780 of file avcodec.h.

◆ chromaoffset

attribute_deprecated int AVCodecContext::chromaoffset
Deprecated:
use encoder private options instead

Definition at line 1785 of file avcodec.h.

◆ mv0_threshold

int AVCodecContext::mv0_threshold

Note: Value depends upon the compare function used for fullpel ME.

  • encoding: Set by user.
  • decoding: unused

Definition at line 1793 of file avcodec.h.

◆ b_sensitivity

attribute_deprecated int AVCodecContext::b_sensitivity
Deprecated:
use encoder private options instead

Definition at line 1798 of file avcodec.h.

◆ color_primaries

enum AVColorPrimaries AVCodecContext::color_primaries

Chromaticity coordinates of the source primaries.

  • encoding: Set by user
  • decoding: Set by libavcodec

Definition at line 1806 of file avcodec.h.

◆ color_trc

enum AVColorTransferCharacteristic AVCodecContext::color_trc

Color Transfer Characteristic.

  • encoding: Set by user
  • decoding: Set by libavcodec

Definition at line 1813 of file avcodec.h.

◆ colorspace

enum AVColorSpace AVCodecContext::colorspace

YUV colorspace type.

  • encoding: Set by user
  • decoding: Set by libavcodec

Definition at line 1820 of file avcodec.h.

◆ color_range

enum AVColorRange AVCodecContext::color_range

MPEG vs JPEG YUV range.

  • encoding: Set by user
  • decoding: Set by libavcodec

Definition at line 1827 of file avcodec.h.

◆ chroma_sample_location

enum AVChromaLocation AVCodecContext::chroma_sample_location

This defines the location of chroma samples.

  • encoding: Set by user
  • decoding: Set by libavcodec

Definition at line 1834 of file avcodec.h.

◆ slices

int AVCodecContext::slices

Number of slices.

Indicates number of picture subdivisions. Used for parallelized decoding.

  • encoding: Set by user
  • decoding: unused

Definition at line 1843 of file avcodec.h.

◆ field_order

enum AVFieldOrder AVCodecContext::field_order

Field order.

  • encoding: set by libavcodec
  • decoding: Set by libavcodec

Definition at line 1849 of file avcodec.h.

◆ sample_rate

int AVCodecContext::sample_rate

samples per second

Examples:
encode_audio.c, output.c, and transcode_aac.c.

Definition at line 1852 of file avcodec.h.

Referenced by add_audio_stream(), init_output_frame(), init_resampler(), main(), open_audio(), and open_output_file().

◆ channels

int AVCodecContext::channels

number of audio channels

Examples:
encode_audio.c, output.c, and transcode_aac.c.

Definition at line 1853 of file avcodec.h.

Referenced by add_audio_stream(), get_audio_frame(), init_converted_samples(), init_fifo(), init_resampler(), main(), and open_output_file().

◆ sample_fmt

enum AVSampleFormat AVCodecContext::sample_fmt

audio sample format

  • encoding: Set by user.
  • decoding: Set by libavcodec.sample format
Examples:
encode_audio.c, output.c, and transcode_aac.c.

Definition at line 1860 of file avcodec.h.

Referenced by add_audio_stream(), init_converted_samples(), init_fifo(), init_output_frame(), init_resampler(), main(), open_audio(), and open_output_file().

◆ frame_size

int AVCodecContext::frame_size

Number of samples per channel in an audio frame.

  • encoding: set by libavcodec in avcodec_open2(). Each submitted frame except the last must contain exactly frame_size samples per channel. May be 0 when the codec has AV_CODEC_CAP_VARIABLE_FRAME_SIZE set, then the frame size is not restricted.
  • decoding: may be set by some decoders to indicate constant frame size
Examples:
encode_audio.c, output.c, and transcode_aac.c.

Definition at line 1872 of file avcodec.h.

Referenced by load_encode_and_write(), main(), and open_audio().

◆ frame_number

int AVCodecContext::frame_number

Frame counter, set by libavcodec.

  • decoding: total number of frames returned from the decoder so far.
  • encoding: total number of frames passed to the encoder so far.

    Note
    the counter is not incremented if encoding/decoding resulted in an error.
Examples:
decode_video.c.

Definition at line 1883 of file avcodec.h.

Referenced by decode().

◆ block_align

int AVCodecContext::block_align

number of bytes per packet if constant and known or 0 Used by some WAV based audio codecs.

Definition at line 1889 of file avcodec.h.

◆ cutoff

int AVCodecContext::cutoff

Audio cutoff bandwidth (0 means "automatic")

  • encoding: Set by user.
  • decoding: unused

Definition at line 1896 of file avcodec.h.

◆ channel_layout

uint64_t AVCodecContext::channel_layout

Audio channel layout.

  • encoding: set by user.
  • decoding: set by libavcodec.
Examples:
encode_audio.c, output.c, and transcode_aac.c.

Definition at line 1903 of file avcodec.h.

Referenced by add_audio_stream(), init_output_frame(), main(), open_audio(), and open_output_file().

◆ request_channel_layout

uint64_t AVCodecContext::request_channel_layout

Request decoder to use this channel layout if it can (0 for default)

  • encoding: unused
  • decoding: Set by user.

Definition at line 1910 of file avcodec.h.

◆ audio_service_type

enum AVAudioServiceType AVCodecContext::audio_service_type

Type of service that the audio stream conveys.

  • encoding: Set by user.
  • decoding: Set by libavcodec.

Definition at line 1917 of file avcodec.h.

◆ request_sample_fmt

enum AVSampleFormat AVCodecContext::request_sample_fmt

Used to request a sample format from the decoder.

  • encoding: unused.
  • decoding: Set by user.

Definition at line 1924 of file avcodec.h.

◆ get_buffer2

int(* AVCodecContext::get_buffer2) (struct AVCodecContext *s, AVFrame *frame, int flags)

This callback is called at the beginning of each frame to get data buffer(s) for it.

There may be one contiguous buffer for all the data or there may be a buffer per each data plane or anything in between. What this means is, you may set however many entries in buf[] you feel necessary. Each buffer must be reference-counted using the AVBuffer API (see description of buf[] below).

The following fields will be set in the frame before this callback is called:

  • format
  • width, height (video only)
  • sample_rate, channel_layout, nb_samples (audio only) Their values may differ from the corresponding values in AVCodecContext. This callback must use the frame values, not the codec context values, to calculate the required buffer size.

This callback must fill the following fields in the frame:

  • data[]
  • linesize[]
  • extended_data:
    • if the data is planar audio with more than 8 channels, then this callback must allocate and fill extended_data to contain all pointers to all data planes. data[] must hold as many pointers as it can. extended_data must be allocated with av_malloc() and will be freed in av_frame_unref().
    • otherwise extended_data must point to data
  • buf[] must contain one or more pointers to AVBufferRef structures. Each of the frame's data and extended_data pointers must be contained in these. That is, one AVBufferRef for each allocated chunk of memory, not necessarily one AVBufferRef per data[] entry. See: av_buffer_create(), av_buffer_alloc(), and av_buffer_ref().
  • extended_buf and nb_extended_buf must be allocated with av_malloc() by this callback and filled with the extra buffers if there are more buffers than buf[] can hold. extended_buf will be freed in av_frame_unref().

If AV_CODEC_CAP_DR1 is not set then get_buffer2() must call avcodec_default_get_buffer2() instead of providing buffers allocated by some other means.

Each data plane must be aligned to the maximum required by the target CPU.

See also
avcodec_default_get_buffer2()

Video:

If AV_GET_BUFFER_FLAG_REF is set in flags then the frame may be reused (read and/or written to if it is writable) later by libavcodec.

avcodec_align_dimensions2() should be used to find the required width and height, as they normally need to be rounded up to the next multiple of 16.

If frame multithreading is used and thread_safe_callbacks is set, this callback may be called from a different thread, but not from more than one at once. Does not need to be reentrant.

See also
avcodec_align_dimensions2()

Audio:

Decoders request a buffer of a particular size by setting AVFrame.nb_samples prior to calling get_buffer2(). The decoder may, however, utilize only part of the buffer by setting AVFrame.nb_samples to a smaller value in the output frame.

As a convenience, av_samples_get_buffer_size() and av_samples_fill_arrays() in libavutil may be used by custom get_buffer2() functions to find the required data size and to fill data pointers and linesize. In AVFrame.linesize, only linesize[0] may be set for audio since all planes must be the same size.

See also
av_samples_get_buffer_size(), av_samples_fill_arrays()
  • encoding: unused
  • decoding: Set by libavcodec, user can override.

Definition at line 2004 of file avcodec.h.

◆ refcounted_frames

attribute_deprecated int AVCodecContext::refcounted_frames

If non-zero, the decoded audio and video frames returned from avcodec_decode_video2() and avcodec_decode_audio4() are reference-counted and are valid indefinitely.

The caller must free them with av_frame_unref() when they are not needed anymore. Otherwise, the decoded frames must not be freed by the caller and are only valid until the next decode call.

This is always automatically enabled if avcodec_receive_frame() is used.

Definition at line 2019 of file avcodec.h.

◆ qcompress

float AVCodecContext::qcompress

amount of qscale change between easy & hard scenes (0.0-1.0)

Definition at line 2022 of file avcodec.h.

◆ qblur

float AVCodecContext::qblur

amount of qscale smoothing over time (0.0-1.0)

Definition at line 2023 of file avcodec.h.

◆ qmin

int AVCodecContext::qmin

minimum quantizer

  • encoding: Set by user.
  • decoding: unused

Definition at line 2030 of file avcodec.h.

◆ qmax

int AVCodecContext::qmax

maximum quantizer

  • encoding: Set by user.
  • decoding: unused

Definition at line 2037 of file avcodec.h.

◆ max_qdiff

int AVCodecContext::max_qdiff

maximum quantizer difference between frames

  • encoding: Set by user.
  • decoding: unused

Definition at line 2044 of file avcodec.h.

◆ rc_buffer_size

int AVCodecContext::rc_buffer_size

decoder bitstream buffer size

  • encoding: Set by user.
  • decoding: unused

Definition at line 2051 of file avcodec.h.

◆ rc_override_count

int AVCodecContext::rc_override_count

ratecontrol override, see RcOverride

  • encoding: Allocated/set/freed by user.
  • decoding: unused

Definition at line 2058 of file avcodec.h.

◆ rc_override

RcOverride* AVCodecContext::rc_override

Definition at line 2059 of file avcodec.h.

◆ rc_max_rate

int AVCodecContext::rc_max_rate

maximum bitrate

  • encoding: Set by user.
  • decoding: unused

Definition at line 2066 of file avcodec.h.

◆ rc_min_rate

int AVCodecContext::rc_min_rate

minimum bitrate

  • encoding: Set by user.
  • decoding: unused

Definition at line 2073 of file avcodec.h.

◆ rc_max_available_vbv_use

float AVCodecContext::rc_max_available_vbv_use

Ratecontrol attempt to use, at maximum, of what can be used without an underflow.

  • encoding: Set by user.
  • decoding: unused.

Definition at line 2080 of file avcodec.h.

◆ rc_min_vbv_overflow_use

float AVCodecContext::rc_min_vbv_overflow_use

Ratecontrol attempt to use, at least, times the amount needed to prevent a vbv overflow.

  • encoding: Set by user.
  • decoding: unused.

Definition at line 2087 of file avcodec.h.

◆ rc_initial_buffer_occupancy

int AVCodecContext::rc_initial_buffer_occupancy

Number of bits which should be loaded into the rc buffer before decoding starts.

  • encoding: Set by user.
  • decoding: unused

Definition at line 2094 of file avcodec.h.

◆ coder_type

attribute_deprecated int AVCodecContext::coder_type
Deprecated:
use encoder private options instead

Definition at line 2105 of file avcodec.h.

◆ context_model

attribute_deprecated int AVCodecContext::context_model
Deprecated:
use encoder private options instead

Definition at line 2111 of file avcodec.h.

◆ frame_skip_threshold

attribute_deprecated int AVCodecContext::frame_skip_threshold
Deprecated:
use encoder private options instead

Definition at line 2117 of file avcodec.h.

◆ frame_skip_factor

attribute_deprecated int AVCodecContext::frame_skip_factor
Deprecated:
use encoder private options instead

Definition at line 2121 of file avcodec.h.

◆ frame_skip_exp

attribute_deprecated int AVCodecContext::frame_skip_exp
Deprecated:
use encoder private options instead

Definition at line 2125 of file avcodec.h.

◆ frame_skip_cmp

attribute_deprecated int AVCodecContext::frame_skip_cmp
Deprecated:
use encoder private options instead

Definition at line 2129 of file avcodec.h.

◆ trellis

int AVCodecContext::trellis

trellis RD quantization

  • encoding: Set by user.
  • decoding: unused

Definition at line 2137 of file avcodec.h.

◆ min_prediction_order

attribute_deprecated int AVCodecContext::min_prediction_order
Deprecated:
use encoder private options instead

Definition at line 2142 of file avcodec.h.

◆ max_prediction_order

attribute_deprecated int AVCodecContext::max_prediction_order
Deprecated:
use encoder private options instead

Definition at line 2146 of file avcodec.h.

◆ timecode_frame_start

attribute_deprecated int64_t AVCodecContext::timecode_frame_start
Deprecated:
use encoder private options instead

Definition at line 2150 of file avcodec.h.

◆ rtp_callback

attribute_deprecated void(* AVCodecContext::rtp_callback) (struct AVCodecContext *avctx, void *data, int size, int mb_nb)
Deprecated:
unused

Definition at line 2164 of file avcodec.h.

◆ rtp_payload_size

attribute_deprecated int AVCodecContext::rtp_payload_size
Deprecated:
use encoder private options instead

Definition at line 2170 of file avcodec.h.

◆ mv_bits

attribute_deprecated int AVCodecContext::mv_bits

Definition at line 2181 of file avcodec.h.

◆ header_bits

attribute_deprecated int AVCodecContext::header_bits

Definition at line 2183 of file avcodec.h.

◆ i_tex_bits

attribute_deprecated int AVCodecContext::i_tex_bits

Definition at line 2185 of file avcodec.h.

◆ p_tex_bits

attribute_deprecated int AVCodecContext::p_tex_bits

Definition at line 2187 of file avcodec.h.

◆ i_count

attribute_deprecated int AVCodecContext::i_count

Definition at line 2189 of file avcodec.h.

◆ p_count

attribute_deprecated int AVCodecContext::p_count

Definition at line 2191 of file avcodec.h.

◆ skip_count

attribute_deprecated int AVCodecContext::skip_count

Definition at line 2193 of file avcodec.h.

◆ misc_bits

attribute_deprecated int AVCodecContext::misc_bits

Definition at line 2195 of file avcodec.h.

◆ frame_bits

attribute_deprecated int AVCodecContext::frame_bits
Deprecated:
this field is unused

Definition at line 2199 of file avcodec.h.

◆ stats_out

char* AVCodecContext::stats_out

pass1 encoding statistics output buffer

  • encoding: Set by libavcodec.
  • decoding: unused

Definition at line 2207 of file avcodec.h.

◆ stats_in

char* AVCodecContext::stats_in

pass2 encoding statistics input buffer Concatenated stuff from stats_out of pass1 should be placed here.

  • encoding: Allocated/set/freed by user.
  • decoding: unused

Definition at line 2215 of file avcodec.h.

◆ workaround_bugs

int AVCodecContext::workaround_bugs

Work around bugs in encoders which sometimes cannot be detected automatically.

  • encoding: Set by user
  • decoding: Set by user

Definition at line 2222 of file avcodec.h.

◆ strict_std_compliance

int AVCodecContext::strict_std_compliance

strictly follow the standard (MPEG-4, ...).

  • encoding: Set by user.
  • decoding: Set by user. Setting this to STRICT or higher means the encoder and decoder will generally do stupid things, whereas setting it to unofficial or lower will mean the encoder might produce output that is not supported by all spec-compliant decoders. Decoders don't differentiate between normal, unofficial and experimental (that is, they always try to decode things when they can) unless they are explicitly asked to behave stupidly (=strictly conform to the specs)
Examples:
transcode_aac.c.

Definition at line 2250 of file avcodec.h.

Referenced by open_output_file().

◆ error_concealment

int AVCodecContext::error_concealment

error concealment flags

  • encoding: unused
  • decoding: Set by user.

Definition at line 2262 of file avcodec.h.

◆ debug

int AVCodecContext::debug

debug

  • encoding: Set by user.
  • decoding: Set by user.

Definition at line 2271 of file avcodec.h.

◆ err_recognition

int AVCodecContext::err_recognition

Error recognition; may misdetect some more or less valid parts as errors.

  • encoding: unused
  • decoding: Set by user.

Definition at line 2291 of file avcodec.h.

◆ reordered_opaque

int64_t AVCodecContext::reordered_opaque

opaque 64-bit number (generally a PTS) that will be reordered and output in AVFrame.reordered_opaque

  • encoding: Set by libavcodec to the reordered_opaque of the input frame corresponding to the last returned packet. Only supported by encoders with the AV_CODEC_CAP_ENCODER_REORDERED_OPAQUE capability.
  • decoding: Set by user.

Definition at line 2313 of file avcodec.h.

◆ hwaccel

const struct AVHWAccel* AVCodecContext::hwaccel

Hardware accelerator in use.

  • encoding: unused.
  • decoding: Set by libavcodec

Definition at line 2320 of file avcodec.h.

◆ hwaccel_context

void* AVCodecContext::hwaccel_context

Hardware accelerator context.

For some hardware accelerators, a global context needs to be provided by the user. In that case, this holds display-dependent data Libav cannot instantiate itself. Please refer to the Libav HW accelerator documentation to know how to fill this is. e.g. for VA API, this is a struct vaapi_context.

  • encoding: unused
  • decoding: Set by user

Definition at line 2332 of file avcodec.h.

◆ error

uint64_t AVCodecContext::error[AV_NUM_DATA_POINTERS]

error

  • encoding: Set by libavcodec if flags & AV_CODEC_FLAG_PSNR.
  • decoding: unused

Definition at line 2339 of file avcodec.h.

◆ dct_algo

int AVCodecContext::dct_algo

DCT algorithm, see FF_DCT_* below.

  • encoding: Set by user.
  • decoding: unused

Definition at line 2346 of file avcodec.h.

◆ idct_algo

int AVCodecContext::idct_algo

IDCT algorithm, see FF_IDCT_* below.

  • encoding: Set by user.
  • decoding: Set by user.

Definition at line 2359 of file avcodec.h.

◆ bits_per_coded_sample

int AVCodecContext::bits_per_coded_sample

bits per sample/pixel from the demuxer (needed for huffyuv).

  • encoding: Set by libavcodec.
  • decoding: Set by user.

Definition at line 2378 of file avcodec.h.

◆ bits_per_raw_sample

int AVCodecContext::bits_per_raw_sample

Bits per sample/pixel of internal libavcodec pixel/sample format.

  • encoding: set by user.
  • decoding: set by libavcodec.

Definition at line 2385 of file avcodec.h.

◆ coded_frame

attribute_deprecated AVFrame* AVCodecContext::coded_frame

the picture in the bitstream

  • encoding: Set by libavcodec.
  • decoding: unused
Deprecated:
use the quality factor packet side data instead

Definition at line 2395 of file avcodec.h.

◆ thread_count

int AVCodecContext::thread_count

thread count is used to decide how many independent tasks should be passed to execute()

  • encoding: Set by user.
  • decoding: Set by user.

Definition at line 2404 of file avcodec.h.

◆ thread_type

int AVCodecContext::thread_type

Which multithreading methods to use.

Use of FF_THREAD_FRAME will increase decoding delay by one frame per thread, so clients which cannot provide future frames should not use it.

  • encoding: Set by user, otherwise the default is used.
  • decoding: Set by user, otherwise the default is used.

Definition at line 2414 of file avcodec.h.

◆ active_thread_type

int AVCodecContext::active_thread_type

Which multithreading methods are in use by the codec.

  • encoding: Set by libavcodec.
  • decoding: Set by libavcodec.

Definition at line 2423 of file avcodec.h.

◆ thread_safe_callbacks

int AVCodecContext::thread_safe_callbacks

Set by the client if its custom get_buffer() callback can be called synchronously from another thread, which allows faster multithreaded decoding.

draw_horiz_band() will be called from other threads regardless of this setting. Ignored if the default get_buffer() is used.

  • encoding: Set by user.
  • decoding: Set by user.

Definition at line 2433 of file avcodec.h.

◆ execute

int(* AVCodecContext::execute) (struct AVCodecContext *c, int(*func)(struct AVCodecContext *c2, void *arg), void *arg2, int *ret, int count, int size)

The codec may call this to execute several independent things.

It will return only after finishing all tasks. The user may replace this with some multithreaded implementation, the default implementation will execute the parts serially.

Parameters
countthe number of things to execute
  • encoding: Set by libavcodec, user can override.
  • decoding: Set by libavcodec, user can override.

Definition at line 2444 of file avcodec.h.

◆ execute2

int(* AVCodecContext::execute2) (struct AVCodecContext *c, int(*func)(struct AVCodecContext *c2, void *arg, int jobnr, int threadnr), void *arg2, int *ret, int count)

The codec may call this to execute several independent things.

It will return only after finishing all tasks. The user may replace this with some multithreaded implementation, the default implementation will execute the parts serially. Also see avcodec_thread_init and e.g. the –enable-pthread configure option.

Parameters
ccontext passed also to func
countthe number of things to execute
arg2argument passed unchanged to func
retreturn values of executed functions, must have space for "count" values. May be NULL.
funcfunction that will be called count times, with jobnr from 0 to count-1. threadnr will be in the range 0 to c->thread_count-1 < MAX_THREADS and so that no two instances of func executing at the same time will have the same threadnr.
Returns
always 0 currently, but code should handle a future improvement where when any call to func returns < 0 no further calls to func may be done and < 0 is returned.
  • encoding: Set by libavcodec, user can override.
  • decoding: Set by libavcodec, user can override.

Definition at line 2464 of file avcodec.h.

◆ nsse_weight

int AVCodecContext::nsse_weight

noise vs.

sse weight for the nsse comparison function

  • encoding: Set by user.
  • decoding: unused

Definition at line 2471 of file avcodec.h.

◆ profile

int AVCodecContext::profile

profile

  • encoding: Set by user.
  • decoding: Set by libavcodec.

Definition at line 2478 of file avcodec.h.

◆ level

int AVCodecContext::level

level

  • encoding: Set by user.
  • decoding: Set by libavcodec.

Definition at line 2573 of file avcodec.h.

◆ skip_loop_filter

enum AVDiscard AVCodecContext::skip_loop_filter
  • encoding: unused
  • decoding: Set by user.

Definition at line 2580 of file avcodec.h.

◆ skip_idct

enum AVDiscard AVCodecContext::skip_idct
  • encoding: unused
  • decoding: Set by user.

Definition at line 2586 of file avcodec.h.

◆ skip_frame

enum AVDiscard AVCodecContext::skip_frame
  • encoding: unused
  • decoding: Set by user.

Definition at line 2592 of file avcodec.h.

◆ subtitle_header

uint8_t* AVCodecContext::subtitle_header

Header containing style information for text subtitles.

For SUBTITLE_ASS subtitle type, it should contain the whole ASS [Script Info] and [V4+ Styles] section, plus the [Events] line and the Format line following. It shouldn't include any Dialogue line.

Definition at line 2602 of file avcodec.h.

◆ subtitle_header_size

int AVCodecContext::subtitle_header_size

Definition at line 2603 of file avcodec.h.

◆ vbv_delay

attribute_deprecated uint64_t AVCodecContext::vbv_delay

VBV delay coded in the last frame (in periods of a 27 MHz clock).

Used for compliant TS muxing.

  • encoding: Set by libavcodec.
  • decoding: unused.
    Deprecated:
    this value is now exported as a part of AV_PKT_DATA_CPB_PROPERTIES packet side data

Definition at line 2615 of file avcodec.h.

◆ side_data_only_packets

attribute_deprecated int AVCodecContext::side_data_only_packets

Encoding only and set by default.

Allow encoders to output packets that do not contain any encoded data, only side data.

Some encoders need to output such packets, e.g. to update some stream parameters at the end of encoding.

Deprecated:
this field disables the default behaviour and it is kept only for compatibility.

Definition at line 2630 of file avcodec.h.

◆ initial_padding

int AVCodecContext::initial_padding

Audio only.

The number of "priming" samples (padding) inserted by the encoder at the beginning of the audio. I.e. this number of leading decoded samples must be discarded by the caller to get the original audio without leading padding.

  • decoding: unused
  • encoding: Set by libavcodec. The timestamps on the output packets are adjusted by the encoder so that they always refer to the first sample of the data actually contained in the packet, including any added padding. E.g. if the timebase is 1/samplerate and the timestamp of the first input sample is 0, the timestamp of the first output packet will be -initial_padding.

Definition at line 2648 of file avcodec.h.

◆ framerate

AVRational AVCodecContext::framerate
Examples:
encode_video.c.

Definition at line 2657 of file avcodec.h.

Referenced by main().

◆ sw_pix_fmt

enum AVPixelFormat AVCodecContext::sw_pix_fmt

Nominal unaccelerated pixel format, see AV_PIX_FMT_xxx.

  • encoding: unused.
  • decoding: Set by libavcodec before calling get_format()

Definition at line 2664 of file avcodec.h.

◆ coded_side_data

AVPacketSideData* AVCodecContext::coded_side_data

Additional data associated with the entire coded stream.

  • decoding: unused
  • encoding: may be set by libavcodec after avcodec_open2().

Definition at line 2672 of file avcodec.h.

◆ nb_coded_side_data

int AVCodecContext::nb_coded_side_data

Definition at line 2673 of file avcodec.h.

◆ hw_frames_ctx

AVBufferRef* AVCodecContext::hw_frames_ctx

A reference to the AVHWFramesContext describing the input (for encoding) or output (decoding) frames.

The reference is set by the caller and afterwards owned (and freed) by libavcodec - it should never be read by the caller after being set.

Definition at line 2697 of file avcodec.h.

◆ apply_cropping

int AVCodecContext::apply_cropping

Video decoding only.

Certain video codecs support cropping, meaning that only a sub-rectangle of the decoded frame is intended for display. This option controls how cropping is handled by libavcodec.

When set to 1 (the default), libavcodec will apply cropping internally. I.e. it will modify the output frame width/height fields and offset the data pointers (only by as much as possible while preserving alignment, or by the full amount if the AV_CODEC_FLAG_UNALIGNED flag is set) so that the frames output by the decoder refer only to the cropped area. The crop_* fields of the output frames will be zero.

When set to 0, the width/height fields of the output frames will be set to the coded dimensions and the crop_* fields will describe the cropping rectangle. Applying the cropping is left to the caller.

Warning
When hardware acceleration with opaque output frames is used, libavcodec is unable to apply cropping from the top/left border.
Note
when this option is set to zero, the width/height fields of the AVCodecContext and output AVFrames have different meanings. The codec context fields store display dimensions (with the coded dimensions in coded_width/height), while the frame fields store the coded dimensions (with the display dimensions being determined by the crop_* fields).

Definition at line 2724 of file avcodec.h.

◆ hw_device_ctx

AVBufferRef* AVCodecContext::hw_device_ctx

A reference to the AVHWDeviceContext describing the device which will be used by a hardware encoder/decoder.

The reference is set by the caller and afterwards owned (and freed) by libavcodec.

This should be used if either the codec device does not require hardware frames or any that are used are to be allocated internally by libavcodec. If the user wishes to supply any of the frames used as encoder input or decoder output then hw_frames_ctx should be used instead. When hw_frames_ctx is set in get_format() for a decoder, this field will be ignored while decoding the associated stream segment, but may again be used on a following one after another get_format() call.

For both encoders and decoders this field should be set before avcodec_open2() is called and must not be written to thereafter.

Note that some decoders may require this field to be set initially in order to support hw_frames_ctx at all - in that case, all frames contexts used must be created on the same device.

Definition at line 2746 of file avcodec.h.

◆ hwaccel_flags

int AVCodecContext::hwaccel_flags

Bit set of AV_HWACCEL_FLAG_* flags, which affect hardware accelerated decoding (if active).

Definition at line 2755 of file avcodec.h.

◆ extra_hw_frames

int AVCodecContext::extra_hw_frames

Video decoding only.

Sets the number of extra hardware frames which the decoder will allocate for use by the caller. This must be set before avcodec_open2() is called.

Some hardware decoders require all frames that they will use for output to be defined in advance before decoding starts. For such decoders, the hardware frame pool must therefore be of a fixed size. The extra frames set here are on top of any number that the decoder needs internally in order to operate normally (for example, frames used as reference pictures).

Definition at line 2769 of file avcodec.h.


The documentation for this struct was generated from the following file: